The shipping industry is vital to commerce in the United States and in most nations around the world. In particular, the trucking industry is one of the most important branches of this industry. It is estimated that at least thirty to forty percent of all goods transported in the United States are hauled by trucks pulling flat bed trailers. The types of materials and commodities hauled on flat bed trailers vary dramatically. For instance, flat bed trailers are often used to transport heavy equipment, wood products, oil field materials, and steel. Many such goods can be hauled safely and with relative ease of securement to the flat bed trailer. However, some materials present difficulties for those in the shipping industry to transport securely and efficiently.
In particular, various types of payloads are difficult to transport on a flat bed trailer because of their large weight and unconventional shapes. On many occasions, payloads such as timber, steel coils, pipes and other cylindrical objects become dislodged from the bed of trailers despite the best efforts of those responsible for shipping such objects. When these massive loads become loose, there is great risk for property damage and accidents causing injury to persons.
Problems frequently occur because the payload becomes loose as a result of large lateral forces that act on the payload when the vehicle engages in a sharp turn. In addition, a payload can become unsecured over time as the vehicle undergoes routine turns and sustains vibrations and natural swaying forces while traveling great distances over roadways. Further, payloads may shift during transit due to the sudden application of the vehicle""s brakes. Payloads can also become loose after the vehicle hauling it reaches a roll over or other extremely unstable situation.
At present, the United States Department of Transportation (xe2x80x9cDOTxe2x80x9d) regulates the trucking industry. Among other things, the DOT places restrictions on the total weight of a vehicle and its payload that can be transported on roadways. For example, under 23 C.F.R. Section 658.17, the maximum gross weight of a vehicle is limited to 80,000 total pounds and 20,000 pounds per axle. Thus, when heavy payloads are being transported, it is important that the mechanisms used to restrain those payloads do not add unnecessary weight to the total payload.
There are presently several devices employed in the trucking industry for securing and shipping heavy payloads. Information relevant to attempts to address these problems can be found in Reitnouer, U.S. Pat. No. 5,425,608; and Borda, U.S. Pat. No. 5,538,376. However, these references suffer from several disadvantages. For instance, the devices rely on the strength of the side rails of the flat bed trailer which are often made of aluminum and have limited capacity to restrain significant weights and forces. The holding chains utilized in these devices can exert forces on the side rails causing the side rails to yield and the chains to become loose. Further, these devices generally do not prevent the payload from becoming unrestrained should the flat bed trailer reach an overturned or other unstable position.
Furthermore, existing devices for restraining payloads also present difficulties in complying with DOT weight limitations. Some devices employ various combinations of holding chains, brackets and tie downs to secure the payload and, as a result, can add significantly to the overall weight of the shipment. The additional weight of these securing devices can result in violations of DOT regulations. This is particularly true where adequate securement of the payload requires multiple securement devices or the device itself requires a large number of heavy holding chains.
This is a continuation-in-part of application Ser. No, 09/528,779, filed on Mar. 17, 2000, and issued as U.S. Pat. No. 6,250,860 on Jun. 26, 2001. Application Ser. No. 09/528,779 claimed and described another invention that has been in use since that time. The general object of the present invention is to provide restraint of heavy payioads under all circumstances, including when the vehicle transporting the payload reaches a turned over or other unexpected position. It is further an object of this invention to provide a securing device that is relatively light in weight. The instant device will not add significantly to the weight of the payload and therefore faacilitates compliance with DOT weight requirements. Further, it is an object of this device to provide a securing device that can be placed at a variety of positions on a vehicle, and, thus, permit the improved restraint of many typos of payloads. It is also an object of this invention to provide a device that is simple to use, thus reducing the risk of human error, and a device that is affordable to manufacture and purchase.
The present invention is directed to a device that satisfies these needs. The device comprises a tensionable member, such as ungalvanized steel wire rope, with a loop on each end. In the preferred embodiment, the tensionable member is partially encased in a conduit with openings on each end, with said tensionable member extending through and beyond the openings at the ends of the conduit. Said conduit is attachable by connecting means to the front to rear frame rails which run lengthwise on the underside of a vehicle such as a flat bed trailer. These frame rails are generally steel I-beams and provide the primary support for the trailer bed. It is widely known that the frame rails are much stronger than the side rails relied upon by other devices and methods currently used in the industry.
The device further includes a plurality of restraining elements such as transport chains. Said transport chains restrain the payload by passing over or through the payload, by passing over or through the side rails of the flat bed trailer, and by being secured to the tensionable member by passing through the loops at the opposite extremities of the tensionable member. The loops of the tensionable member may be encased in what is commonly referred to in the industry as wire rope thimbles to provide protection against wear and deformation of the loops. Each of said loops may be formed by wrapping a free end of the tensionable member around one of said thimbles and coupling said free end of the tensionable member with a portion of the tensionable member in between the loop and the opening of the conduit. To further secure the coupling, said free end may be crimped against or wrapped around said tensionable member. To achieve still further securement, said coupling may be encased in a durable sleeve. It will be appreciated that said sleeve will provide protection against wear and deformation of the coupling. According to tests performed by the inventor, the load limit of the present invention substantially exceeds the requirements applicable in the industry. At the same time, the total weight of the device is about 45 pounds which is believed to be significantly less than other devices currently used to restrain payloads.
Tightening of said transport chains over the payload and to the tensionable member is achieved by using ratchet binders or other tightening means, such as lever binders or turn buckles. Said tightening means may be located adjacent to the surface of the trailer bed and are therefore more easily accessed by the driver for periodic examination to ensure proper restraint of the payload, thereby achieving advantages over other methods cuffently used.
The present invention can be adapted for use on various types and sizes of flat bed trailers and potentially other vehicles without significant modifications to such vehicles. In addition, the present invention is adjustable and can be used at most any desired location on the flat bed trailer. More than one of the devices may be used on a flat bed trailer to provide additional restraint to the particular payload being hauled. In addition, because it has relatively few parts, the present invention is easy to use and install and is affordable.